This is a renewal application to support 10 graduate students in their second year of a Ph.D. Program in Genetics and Genomics (PGG) at Harvard Medical School. The goal of this program is to provide our students with comprehensive and rigorous training in genetics, including quantitative analysis of genetic and genomic data. This training comes from coursework, program activities, and dissertation research. The students have the opportunity to carry out Ph.D. research in one of several laboratories, centered around, but not exclusive to, the Department of Genetics. The laboratories of training grant faculty cover a wide range of research areas, ranging from prokaryotic gene regulation to human biology and disease. Students supported by the training grant are part of the Biological and Biomedical Sciences (BBS) program, a large umbrella program that includes six departments. However, PGG students participate in a program that is distinct from the rest of BBS students in its focus on genetics and genomics. PGG students are self-selected for the program based on their expressed interest in the program during their first or second year of graduate school and their choice of dissertation laboratory. Students in the program are required to concentrate their course work in genetics and genomics, including a requirement to take a course in the quantitative analysis of biological data. Our students will be guided in choosing courses and rotations by faculty advisors who are part of the PGG. PGG students will also participate in a set of programmatic activities, including (1) an annual symposium, (2) monthly meetings that will allow them to talk about their own research, to interact with senior students, and to interact with postdocs, including those studying clinical genetics, and (3) the opportunity to invite and host two outside seminar speakers each year. Students will be monitored for progress towards a Ph.D. by their dissertation advisory committees, which will include, in addition to the dissertatio advisor, at least one PGG faculty member. Furthermore, students will write abstracts and present their work by either a poster or a talk at our annual symposium. Taken together, this training plan should provide outstanding training for our students to become highly productive independent investigators in the areas of genetics and genomics.